1. Field of the Invention
Embodiments disclosed herein relate to a robot.
2. Description of the Related Art
Conventionally, a so-called horizontal articulated robot is known as a robot for transferring a substrate such as a semiconductor wafer or the like. In the horizontal articulated robot, a hand serving as an end effecter is installed in the tip end portion of a swingable arm so as to horizontally rotate with respect to the arm. The hand is capable of holding a substrate (see, e.g., Japanese Patent Application Publication No. 2011-224743).
In the robot of this type, a hand drive mechanism for driving the hand is usually arranged within a housing of the arm. For example, a speed reduction device employing a gear mechanism such as a Harmonic Drive (registered trademark) speed reduction mechanism is generally used as the hand drive mechanism.
However, if the conventional speed reduction device employing the gear mechanism is used as the hand drive mechanism as in the conventional configuration stated above, the weight of the arm gets increased. Moreover, it becomes difficult to make the arm slim.